Ottilie I cannot get TabithaWren out of my head, such a stunning combo. I've never considered Tabitha before but with Wren its brought to life, if you don't use it I may steal it ( not for a good few years yet though). Seriously gorgeous!!

I like Calypso quite a bit (some of the sound-similars are nice too-- Callista, Calixta, (sp?) etc). It has a nice sound quality to it. Alcyone is nice too. I think that could definitely work for you.Aphrodite I'm not a fan of. Venus isn't my favorite either, but it feels a bit more down-to-earth then Aphrodite to me. Aphrodite feels a bit too much like an in-your-face beauty name to me, a beauty who flaunts it.
After letting it settle a bit, I think my original expression of Pandora has changed a bit. I like it more than previously expressed.
And whatever name you choose, don't let Illyria slip away! That's possibly my favorite of all the various names in the mix.
I wish I had some more suggestions to give you, but I feel like any name I could suggest that you would like has probably already been on your radar at some point.

From all of your new names, I love Calypso the most. I think it's okay for you to use it.

And btw, am I the only one who 'see' Aphrodite and Venus with different colours? I know it's the same goddess, but.. for me, Aphrodite is blue/green as I identified her with her birth from the sea. Venus is golden/orange/reddish to me. Maybe it sounds weird. I do love mythology, but with Venus I always thought about the planet first rather than the roman goddess.

Sorry for being no help. I wish you find the perfect name soon and, hopefully, keep the Illyria part. Unlike Rosalind, it's the name you love from the beginning, isn't it?!